Foundation Framework General Purpose Classes
The Foundation Framework defines a base layer of APIs that can be used for any type of Objective-C program. It includes root object classes, classes for basic data types such as strings, wrapper classes for primitive data types, and collection classes for storing and manipulating other objects, as well as classes for system information, networking, and other functionality. Mastering the Foundation Framework APIs is one of the keys to becoming a proficient Objective-C programmer. Part 3 will help you get there as you examine these APIs in depth.